A major question i get re research on cognitive neuroscience and meditation is whether it is really possible for the brain to alter its functional patterns significantly, and in "reasonable" times. A way to look a this is just how creative the brain is at working out alternatives when there is major injury, disease, birth defect which results in the loss of much or all of our sight. The brain annexes adjacent available "real estate" and "repurposes" it, or diverts, combines or modifies existing functionality to optimize sensing abilities that are available so that a new capability results.
Recent work also demonstrated that the traditional five senses are augmented by other functions, which some regard as senses, like balance, limb positioning, hunger, thirst, temperature sensing, time, pain, and the ability to process faces or shapes. Even the mind is classified as a sense in many traditions. These senses are not simple. Even touch, for example, is very complex. It is astonishing how "touch" is able to sense just how wet, hot, sharp, rough, etc. something is.
When there is an evolutionary need, the brain can make major modifications of existing optical system elements to generate important capabilities. An example is the rods and cones in our eyes, which were discovered 150 years ago, and which were regarded as the only light-sensitive cells in the human body. New research changed that perception.
Russell Foster, of Oxford, a circadian rhythm specialist, was fascinated by how mice, like people, adjust their behavior to new day-night cycles; however, when mice had no eyes, they couldn't. But if the mice were blind as a result of not having any rod or cones, they WERE able to reset their daily clocks. Foster was quoted as saying "There had to be some other weird photoreceptor residing in the eye, but what the bloody hell was it?"
Foster did not discover the weird photoreceptor, but his grad student Ignacio Provencio, now @ UVA, discovered a protein that makes some skin cells in frogs darken when exposed to light. These cells were found in the retina, also of humans and mice, but were not rods or cones. They were modified ganglion cells which normally carry signals from rods and cones along the optic nerve. The "weird photoreceptor" was found.
Foster later found a woman who had a rare genetic disorder that had destroyed her rods and cones but left her with her ganglion cells intact for circadian signaling.
Other researchers found that the messaging route from these modified ganglion cells went not just to a small clump of neurons for regulating circadian rhythms, the suprachiasmatic nucleus. Other brain centers responsible for shifting the gaze, regulating fear and pain, and dilating the pupils were also destinations. No one had known until now how these critical functions were performed.
Another example of the brain's adaptation is the phenomena of "blindsight", or "knowing", somehow, that there was a chair in the way, or a moving object and how it was moving, even with a severely damaged optical cortex, the primary visual processing center, which made them blind. Blindsight is a "work around" of the non-functional normal processing pathway to the visual cortex.
Normally the optical cortex sends the signals to both a) the memory for identification of objects and several cortical regions for deeper processing and b) to more primitive parts of the brain which control fast reflexive movements, i.e. fight or flight.
However, with a damaged optical cortex, visual information is sent directly to the motor cortex which controls movement of limbs, etc. without ever going to the optical cortex. Amazingly, some folk with "blindsight" can "know" whether someone is happy or angry, when postures are threatening, or facial muscles flexed and pupils dilated - all signals of concern. Knowing how severe the threat was, the movement of limbs would be activated rapidly even without conscious "sight" of the threat. The body was protected, even when a threat was present, but invisible.
IME, a particularly interesting capability has been developed by the brain to use sound to compensate for the loss of sight. Some folk are able, like bats, dolphins, or submarine sonars, to echolocate. By sending out a sound, and listening to how it is changed by what it bounces off of, one can tell how far away something is, what direction it is, and its structural character.
Daniel Kish, who lost his sight as a one year old, is able to go dancing, hiking in the dark and ride his bike in city traffic as you can see on youTube. The scenes he describes have form, depth and texture, but no color. Ben Underwood is another echolocator captured on youTube.
Experiments on "echolocators" have shown that the VISUAL cortex was activated when echoes were heard; the AUDIO cortex, which normally handles sound, appeared to play no special role in making images from echoes; a fascinating example of the brain repurposing an input and a non-traditional center for that input to solve a problem.
As Daniel Kish shows in the video, it is possible to learn how to do it yourself. In a completely unscientific experiment, i tried this, and it appears to work. Given that my ears are not the best, (rock music and living over a factory until i was 18), it was surprising that it worked at all. Would strongly recommend you check it out.
Given the brain's great capability as an innovator and problem solver demonstrated in these instances, it is clearly capable of changing the routing through a few processing centers such as we are seeing in cognitive neuroscience and meditation.
Recent work also demonstrated that the traditional five senses are augmented by other functions, which some regard as senses, like balance, limb positioning, hunger, thirst, temperature sensing, time, pain, and the ability to process faces or shapes. Even the mind is classified as a sense in many traditions. These senses are not simple. Even touch, for example, is very complex. It is astonishing how "touch" is able to sense just how wet, hot, sharp, rough, etc. something is.
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| Russell Foster |
Russell Foster, of Oxford, a circadian rhythm specialist, was fascinated by how mice, like people, adjust their behavior to new day-night cycles; however, when mice had no eyes, they couldn't. But if the mice were blind as a result of not having any rod or cones, they WERE able to reset their daily clocks. Foster was quoted as saying "There had to be some other weird photoreceptor residing in the eye, but what the bloody hell was it?"
 |
| Ignacio Provencio |
Foster later found a woman who had a rare genetic disorder that had destroyed her rods and cones but left her with her ganglion cells intact for circadian signaling.
 |
| Modified Ganglion Cells (ipRCC) encode and transmit light into non image-forming centers |
Other researchers found that the messaging route from these modified ganglion cells went not just to a small clump of neurons for regulating circadian rhythms, the suprachiasmatic nucleus. Other brain centers responsible for shifting the gaze, regulating fear and pain, and dilating the pupils were also destinations. No one had known until now how these critical functions were performed.
 |
| Visual System |
Normally the optical cortex sends the signals to both a) the memory for identification of objects and several cortical regions for deeper processing and b) to more primitive parts of the brain which control fast reflexive movements, i.e. fight or flight.
However, with a damaged optical cortex, visual information is sent directly to the motor cortex which controls movement of limbs, etc. without ever going to the optical cortex. Amazingly, some folk with "blindsight" can "know" whether someone is happy or angry, when postures are threatening, or facial muscles flexed and pupils dilated - all signals of concern. Knowing how severe the threat was, the movement of limbs would be activated rapidly even without conscious "sight" of the threat. The body was protected, even when a threat was present, but invisible.
Daniel Kish, who lost his sight as a one year old, is able to go dancing, hiking in the dark and ride his bike in city traffic as you can see on youTube. The scenes he describes have form, depth and texture, but no color. Ben Underwood is another echolocator captured on youTube.
Experiments on "echolocators" have shown that the VISUAL cortex was activated when echoes were heard; the AUDIO cortex, which normally handles sound, appeared to play no special role in making images from echoes; a fascinating example of the brain repurposing an input and a non-traditional center for that input to solve a problem.
As Daniel Kish shows in the video, it is possible to learn how to do it yourself. In a completely unscientific experiment, i tried this, and it appears to work. Given that my ears are not the best, (rock music and living over a factory until i was 18), it was surprising that it worked at all. Would strongly recommend you check it out.
Given the brain's great capability as an innovator and problem solver demonstrated in these instances, it is clearly capable of changing the routing through a few processing centers such as we are seeing in cognitive neuroscience and meditation.
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